Electric Current Converter
Convert Amperes, Milliamperes, Kiloamperes, and more.
Typical Current Values
| Device / Scenario | Amperes (A) | Milliamperes (mA) |
|---|---|---|
| LED Indicator | 0.02 A | 20 mA |
| USB Charger (Standard) | 1 - 2.4 A | 1000 - 2400 mA |
| Toaster | ~6 - 10 A | ~6000+ mA |
| Car Starter Motor | ~150 - 200 A | 150,000+ mA |
What is Electric Current?
Electric current is the flow of electric charge carried by moving electrons in a wire. It measures the rate at which charge passes a given point.
Unit Explanations
Ampere (A)
The SI base unit of electric current. It is named after André-Marie Ampère.
Milliampere (mA)
One thousandth of an ampere (0.001 A). Commonly used for small electronics, LEDs, and batteries.
Biot (Bi)
Also known as Abampere (abA). It is the CGS electromagnetic unit of current. 1 Bi = 10 A.
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Understanding Electric Current
Electric current is the lifeblood of every electronic device, from the smartphone in your pocket to the power grid lighting your city. Measured in Amperes (A), current describes the rate at which electric charge flows through a conductor. Our Electric Current Converter lets you instantly switch between Amps, Milliamps, Microamps, and Kiloamps—essential for engineers, hobbyists, and electricians alike.
Current Units Explained
Ampere (A)
The SI base unit for electric current. One Ampere is the flow of one coulomb of charge per second. Your household wiring typically handles 15-20A. Electric stoves can draw 30-50A.
Milliampere (mA)
1 mA = 0.001 A. The standard unit for consumer electronics. Your phone charger might draw 500-2000mA. Battery capacity is often rated in mAh (milliamp-hours).
Microampere (µA)
1 µA = 0.000001 A. Used in low-power electronics like sleep-mode currents for IoT sensors, or the current draw of a modern wristwatch.
Kiloampere (kA)
1 kA = 1000 A. Reserved for industrial applications. Short-circuit currents in power grids can reach tens of kiloamperes, requiring specialized protective equipment.
Ohm's Law: The Holy Trinity
The relationship between Voltage (V), Current (I), and Resistance (R) is defined by Ohm's Law:
V = I × R
Rearranged: I = V / R and R = V / I.
If you know any two of these values, you can calculate the third. This is the single most important equation in electrical engineering.
Practical Applications
Battery Life Calculation
A 3000mAh battery powering a device that draws 100mA will last approximately 3000/100 = 30 hours. Converting mA to A is crucial when comparing device specs to battery ratings.
Electrical Safety
Circuit breakers are rated in Amps. A 15A breaker will trip if the circuit draws more than 15 Amps, protecting wires from overheating. Understanding current ratings prevents fires and electrical hazards.
Power Supply Sizing
If your project draws 2.5A, you need a power supply rated for at least 2.5A (ideally with 20% headroom, so 3A). Undersized supplies overheat or fail to deliver stable voltage.
Frequently Asked Questions
What is the Ampere (A)?
The Ampere (symbol: A), often shortened to 'Amp', is the SI base unit of electric current. It is defined as the flow of one coulomb of electric charge past a point in one second. Named after French physicist André-Marie Ampère, it is fundamental to all electrical measurements.
How do I convert Milliamps (mA) to Amps (A)?
To convert mA to A, simply divide by 1000. For example, 500 mA = 500 / 1000 = 0.5 A. Our converter does this instantly for any value you enter.
What is Microampere (µA) used for?
Microamperes (1 µA = 0.000001 A) are used to measure extremely small currents. You will see this unit in sensor datasheets (like accelerometers or light sensors), pacemaker battery draw, and low-power IoT devices designed to run for years on a small battery.
When would I use Kiloamperes (kA)?
Kiloamperes (1 kA = 1000 A) are used for high-power industrial applications. Examples include short-circuit ratings of circuit breakers, arc flash calculations, and the current capacity of power substation equipment.
What is Ohm's Law?
Ohm's Law is the foundational equation of electrical circuits: V = I × R (Voltage = Current × Resistance). If you know any two values, you can calculate the third. For example, a 12V battery pushing current through a 4Ω resistor will have a current of 12/4 = 3 Amps.
What does 'mAh' mean on a battery?
mAh (Milliamp-hours) is a measure of battery capacity, not current directly. A 2000mAh battery can theoretically supply 2000mA (2A) for 1 hour, or 200mA for 10 hours. To calculate runtime: Hours = Battery Capacity (mAh) / Device Current Draw (mA).
How much current is dangerous to humans?
Current, not voltage, kills. Even 10-20 mA of AC current across the heart can be lethal. Below 1 mA is generally not felt. This is why electrical safety focuses on grounding and GFCI protection, which disconnect circuits if current flows through an unintended path (like a person).
What is the difference between AC and DC current?
DC (Direct Current) flows in one constant direction (like from a battery). AC (Alternating Current) reverses direction periodically (like household mains power at 50/60 Hz). AC is preferred for power grids because it can be easily transformed to higher voltages for efficient long-distance transmission.
How do I measure current in a circuit?
You measure current using an ammeter or a multimeter set to current mode. Crucially, the meter must be connected in series (breaking the circuit and inserting the meter into the path). Never connect an ammeter in parallel – this creates a short circuit and can damage the meter or start a fire.
What is 'Current Draw' of a device?
Current draw is the amount of current a device consumes during operation. It is specified in Amps or milliamps. Knowing this value is essential for choosing the right power supply (which must have a current rating equal to or greater than the device's draw) and for calculating battery life.